Clasby's in Norway

This is kinda odd, I just search the web for my middlename and I found this forum. My Grandfather emigrated from England to norway after world war II , his name was James Alfred Clasby. Before he died he did som research about the Clasby clan,and I think he said that he came almost back to 1600 B.C. but I can't confirm that :O( I know some of his cussins or something was departed to Australia because he stole a bread or something like that. It would be really nice to hear if someone knows something :O)